JavaScript 位运算及实际应用实例

const a = 120; // 0b000...1111000
const b = 11; //  0b000...0001011
a & b; // 8 = 0b000...1000

const a = 5; // 0b000...0101
const b = 3; // 0b000...0011
a | b; // 7 = 0b000...0111

const a = 5; // 0b000...0101
const b = 3; // 0b000...0011
a ^ b; // 6 = 0b000...0110

const a = 9; // 0b000...001001
const b = 2;
a << b; // 36 = 0b000...100100

const a = 36; // 0b000...100100
const b = 2;
a >> b; // 9  =  0b000...001001

function isPowerOfTwo(n) {
    return n > 0 && ((n - 1) & n) === 0;
}

function isOdd(n) {
    return (n & 1) === 1;
}

const canFly = 1 << 0;
const canRun = 1 << 1;
const canSwim = 1 << 2;
const canJump = 1 << 3;
let flags = 0;
// 添加标志
flags |= canFly;
flags |= canJump;
// 判断标志
!!(flags & canFly); // true
!!(flags & canJump); // true
// 清除标志
flags &= ~canFly;
!!(flags & canFly); // false